The cultivation period effects on heavy metals content of some soils of Sohag governorate

Document Type : Research and Review Papers

Authors

1 Division of Soil and Water Sciences, Faculty of Agriculture, Sohag University

2 Geology Department Faculty of Science Sohag University Sohag Egypt 82524

3 Soils and Water Department Faculty of Agriculture Sohag University Sohag Egypt 82524

Abstract

The main objectives of this study are to assess the levels of
some heavy metals (i.e. Mn, Cd, Zn, Co, and Cu) in some soils
of Sohag governorate under different lands in the respect of
cultivation period; and to quantify the metal contamination of
these soils. Total number of 114 soil samples was collected
from 57 different locations under various land-uses (i.e. old
cultivated lands, new cultivated lands, and un-cultivated lands).
Un-cultivated soils are considered as a control soil, while old
cultivated soils are the oldest soils compared to new reclaimed
ones in between. Soil samples were collected from two layers 0-
30 cm and 30-60 cm depth to reflect the various fertilizers
application used in studied soils. The geo-coordinates of the
studied sites were identified using the global Positioning System
(GPS). Soil samples were prepared and analyzed for their
physicochemical properties as well as for their content of
DTPA-extractable heavy metals in the soil testing laboratories
using the standard methods of analysis. Maps of DTPAextractable
heavy metals were generated. Correlations between
the concentration of the studied elements and some soil
properties (i.e. primary sand, silt, clay, pH, OM, CaCO3) was
developed whereas, a positive correlation was observed between
clay content and heavy metal. The obtained results indicated
that the highest concentrations of heavy metals were found in
the old cultivated soils compared to un-cultivated soils and
newly reclaimed soils. Therefore, it should be mentioned that,
the cultivation period affects the levels and quantities of these
heavy metals in the studied soils. This may be due to
agricultural activities such as the use of chemical fertilization.

Keywords